Boring-bar.



PATENTED FEB. 4, 1908.

0. L. RIKE'R, JR. BORING B R. APPLICATION PILED'EAR, 15. 1907.

inventors Garroil; LRikem/rr.

Witnesses.

his Attorney UNITED STATES CARROLL L. BIKER, JR., OF NEW YORK, N. Y.

BORING-BAR.

I l Specification of Letters Patent.

. Patented Feb. 4, 19.08.

Application filed March 16. 1907- Serial No. 362.498-

To all whom it may concern.

Be it known that I, CARROLL LIVINGSTON RIKER, Jr., a citizen ofthe United States, residing in New York, in the county of Kings and State of New York, have invented certain new and useful Improvements in Boring-Bars, of which the following is a specification.

- This invention relates to boring bars and particularly to the manner of securing and adjusting the cutter carried by the bar. This bar is not only useful in connection with milling machines, but with boring machines generally and also wood working tools.

The invention comprises mechanism for controlling the cutter; that is advancing or retracting it not only preliminary to making a cut, but also to do this recisely during the time the cut is being ma e.

In the drawing accompanying and forming a part of this specification Figure 1 is alongitudinal section of the boring bar equipped with my present improvement. It is shown here in connection with a portion of a steady bar or steady arm. Fig. 2 is an enlarged view of a portion of the device illustrated in Fig. 1 showing the cutter and thesliding key for advancing and retracting the cutter. Fig. 3 is an enlarged end view looking at the bar from the right hand end of Fig. 1. Fig. 4 is a cross section through Fig. 2. Fig. 5 is a front view of the cutter rack. Fig. 6 is a view similar to Fig. 4. Figs. 7 and 8 are views in transverse positions of the sliding key for controlling the cutter; and Fig. 9 is a side view of the split thimble for engaging the sliding key.

The boring bar or the main portion of this is designated in a general way by 10 and is shown as having a tapered end 11 for engaging a chuck, and a screw-threaded socket illustrating the general surroundings of the structure. The bar is shown as having a cutter opening 16 through it for receiving a cutter 17 and it is principally with the advancing' and retracting of this cutter from and toward the axis of the cutter bar that the present invention is concerned. The boring at has a longitudinally disposed cavity 18 for receiving an actuator for the cutter. Within the cavity 18 is located a sliding key,

designated in a general way b 19, and which carries a rack 20 having slanting teeth, in the present instance illustrated at an angle of about 15 degrees. The cutter opening 16 passes through or intercepts the cavity 18 which cavity in the present instance is shown poncentrica ly disposed within the bore in the MU. The cutter carries teeth, in the resent illustration its body has a recess wlthin it for receiving the cutter rack 21 which has slanting teeth mating with the teeth on the rack 20. These teeth are at rather an acute angle to the normal so that the parts will operate easil Accurate adjustment is rendered ossible with this form of rack, a relatively long movement of the actuator being required for effectin a short movement of the cutter. The rac 21 is shown as comparatively thin and having a nose 22 for engaging a socket in the cutter. Upon the reciprocation of the sliding key the slidin engagement between the slanting teeth 0 the racks 20 and 21, will reciprocate the cutter, in the present instance transversely to the direction of the movement of the sliding key. The sliding key has at one end a groove 24 for running on pins 25 in the cavity 18. This will prevent rotation of the key. The shank 26 of the key is screw threaded and this is so off-set from the body of the sliding key that it will be eccentrically disposed relative to the borin bar as a whole.

A split thimbTe illustrated in Fig. 9 and designated in a general way by 30 has a screw-threaded end 31 for engaging the screw-threaded shank 26 and an adjusting nut 32 will engage the outer screw-threads ried by a thimble nut 38 will engage. The

head 39 of the thimble nut engages a shoulder 40 formed on the outer end of the boring bar body. This nut embraces a portion 41 of the thimble and is held between the shoulder and a collar 42 which is pinned upon a portion 43 of the thimble 30. The thimble nut may have a Wrench engaging head 44, and the collar. may have a scale 45 applied to it. The split end of the thimble 30 is shown as having a wrench engaging portion 46 whereb it may be turned.

There is a c ear or blank space indicated at 47 at each end of the rack 20 and this will permit the removal of the cutter and the rack 22 at either end of the limit of movement ofthe rack 20 so that if the rack is moved to the full extent of its movement and still the tool is not adjusted to the extent desired the tool may be released from the rack and moved by hand to about the desiredposition and then caused to engage the rack. The tool is steadied by means of a spring slot facing 48 upon one side and a s ring slot facing 49 which enga es the rac and is/ bowed around the sli ing key. This will prevent the tool from slipping during periods of adjustment and when it has not been locked in position, and also furnishes a hard facing which may be renewed when worn.

The means for locking the tool in position in the resent instance is shown as comprising a s eeve 50 mounted upon the bar and adapted to clasp the cutter when moved toward the cutter. For moving the sleeve 50 toward and against the cutter a collar 51 having a working fit with the bar and engaging the end of the sleeveis provided, and

there is a flange portion 52 of this collar large enough to pass over the screw threads 53 upon the bar, which screw threads are engaged by a pair of nuts 5455 for advancing the collar and sleeve and for locking the samein their positions of adjustment; This may be adjusted so as to afford sufficient clamping to produce the desired ease of working fit or may be advanced with suflicientfirmness against the cutter to clamp the same inpositlon. I v

The operation of the invention is substantially as follows: When the bar has been placed in position in the machine with which it is intended to be used, as for instance having the engaging end 11 properly seated in some suita le form of 'chuck, and if occasion may demand, having the end 13 su ported by the steady arm of the machine, t e work having previously been placed with the bar passing through that o ening of it which is to be bored, the tool wi 1 be advanced to approximately the proper distance by rotating the split thimble 30 by means of its wrench on aging portion 46, and then micrometer ad ustment will be had by rotating the thimble nut 38. The engagement between the racks 2O and.21 will cause a movement of the cutter inward or outward as occasion s'meao may demand. After the cutter has been moved to the proper position it may be located by advancing the sleeve 50 against it, the advance of the sleeve being effected by the nuts 5455.

Although Fig. 4 shows a boring cutter, yet it will be apparent that this invention is equally useful in connection with facing cutters and other tools which may be mounted upon a boring bar.

When it is desired to slightly change the position of the tool the split thimble will be rotated .and the racks will slide one in the other and advance or retract the tool as oc' casion may demand. When considerable movement is required of the tool, or it is desired to remove the tool, and it would require a reat many rotations of the s lit thimble to e ect the desired movement 0 the tool, it will merely be necessary to unscrew the screw thimble 38, slide the sliding key out of the bar, effect the proper adjustment, and replace the parts in position, after which the micrometer ad'ustment may be effected by means of rotating the split thimble.

Having described my invention I claim:

1. The combination in a boring bar, of a bar member havin an axially disposed chamber, a key sliifable in said chamber, means for preventing the rotation of the key, said key having tool enga ing faces, said bar being provided with a too seat transversely disposed to said chamber, a tool carrying key engaging faces mounted in said tool seat and enga ing the said faces on the slidin key, said key aving a shank rovided wit a screw thread, a split thim le having a chamber within it for receiving said shank and having a portion of the walls of such chamber screw threaded for engagement with said screw thread, the split in said thimble extending through said screw threaded ortion, a clamping nut for binding said sp it thimble upon the shank of the key, a screw threaded thimble rotatably mounted upon the end of the split thimble and prevented from reciprocation thereon and havin screw threaded engagement With'the boring bar.

2. The combination in a boring bar, of a bar member havin an axially disposed chamber, a key slidable lIl said chamber, means for preventing the rotation of the key, said key aving slanting rack teeth upon it and 0 en s'paces'at the ends of the rack teeth, said ar being provided with a tool seat transversely disposed to said axial chamber, a tool carrying rack in said tool seat for engaging with the rack on the sliding key, and means for actuating said key.

3. In a boring bar, the combination of a bar member having any axially disposed cav-' tation*of the key and said key having a screw threaded shank longer than said rack,-

a toolway passing through the bar and inter secting the cavity therein, a tool mounted in 1 said toolway and (provided with a socket, a rack engaging sai tool and having a nose seated in said socket, said rack having teeth for mating with the teeth upon said key and said ke having at the ends of the rack s aces or permitting the disengagement of t e racks, and means for actuating said sliding key.

4. In a boring bar, the combination of a bar member having a cavity, the open end of said cavity being enlarged and having 'a coarse screw thread upon its walls, a sliding keymounted insaid cavity and rovided with 'tool engaging faces, a too way passing through the bar and intersecting the cavity therein, 'atool mounted in said toolway and provided with faces for engaging the faces on the key, a split thimble within, it for receiving the screw threaded shank of the key and provided at its end with aving a chamber 4 thimble mounted upon said split thimble for rotation, a air of collars fast upon said split thimble an threaded thimb e for preventin the longitudinal movement of said split thimble, said screw threaded thimble being provided with coarse threads engaging those on the end of the cavity in the bar member.

Signed at Nos. 9 to 15 Murray street, New York, N. Y.', this 2nd day of March, 1907.

CARROLL L. BIKER, JR.

Witnesses:

FRED. J. DOLE, HENRY E. GREENWOOD.

englaging the ends of said screw 

